weight gain

Stephanie • im 26 and have 2 amazing kids with my ex. i just found out im pregnant with my rainbow baby by my boyfriend of 3 years due December 30

so I'm currently 20 weeks 3 days.

when I started I was 167. went down to 165 went up to 167 at my 16 week scan.

I just stepped on my cousins scale and I'm 172. so only about 5lb gain

should I be worried I'm not gaining